PROCESS FOR PRODUCTION OF POLYAMIDEIMIDE RESIN MICROPARTICLES, AND POLYAMIDEIMIDE RESIN MICROPARTICLES

摘要

The present invention provides a process to produce fine particles of polyamide-imide resin that can be carried out industrially by simple operations with a high reproducibility. It also provides very fine PAI resin particles with a uniform particle size. The invention provides a production process for fine PAI resin particles comprising a dissolution steps and a precipitation step as described below:
[Dissolution step] A step selected from the undermentioned steps (a1) and (b1)
(a1) PAI resin is dissolved in an organic solvent to prepare a PAI resin solution A1 having a PAI resin content of less than 5 mass%,
(b1) PAI resin is dissolved in an organic solvent to prepare a PAI resin solution B1 having a PAI resin content of less than 10 mass%.
[Precipitation step]
(a2) The PAI resin solution A1 is added to a solvent that is virtually free from surface active agents and able to precipitate fine PAI resin particles, in order to cause the precipitation of fine PAI resin particles,
(b2) The PAI resin solution B1 is subjected to flash crystallization to cause the precipitation of fine PAI resin particles.